Production of pile-surfaced materials



p 12, 1939- H. A. WINTERMUTE 2,173,032

PRODUCTION OF PILE SURFACED MATERIALS Filed Nov. 23, 1933 3 Sheets-Sheet1 Sept. 12, 1939. H A. WINTERMUTE 4 PRODUCTION OF PILE SURFACEDMATERIALS I Filed Nov. 23, 1933 3 Sheets-Sheet 2 dbbozmw Sept. 12, 1939.H. A. WINTERMUTE 2,173,032

PRODUCTION OF FILE SURFACED MATERIALS Filed Nov. 23, 1953 a Sheets-Sheets Patented Sept. 12, 1939 Harry A. Winter-mute, Plainfleld, N. 1.,asizignor,

by mesne assignments, to Bohr-Manning Corporation, a corporation ofMassachusetts Application November 23, 1933, Serial at. 699,456

/ 31 Claims.

This invention relates to the production of piled surfaces and pilesurfaced materials and is particularly directed to apparatus and methodsof operation adapted for the eflicient production 5 of such surfaces andsurfaced materials by a process which involves positioning anadhesivecoated foundation material in an electric field and supplyingpile-forming fibers thereto while in said field. l It has been foundthat the production of piled surfaces by electrically depositing fibersand the like by said process can be advantageously car ried out by meansof the apparatus and methods of operating which are to be describedherein- 15 after.

Among the novel features and objects of the present invention areincluded the use of a stream of air or other gas to disentangle the pileforming fibers and to carry them as individual 20 suspended particlesinto the electric field for deposition on the surface to be piled.Further objects of the invention are to use said stream of gas toprevent or break up the treeing of the fibers as they approach thesurface to be 25 piled, to return for representation fibers that are notattached when first presented for deposition,

to supplement the force of gravity and the electrical forces availablein moving the fibers towards the surface to be piled and to provide 30methods of controlling the relative humidity and other gas conditionswithin the apparatus in which the pile formingoperations are carried on.Other objects comprise the use of auxiliary electrodes to provideeflicient, safe, and conveni- 3 ent control of the electrical forces andthe use of special electrical circuits to prevent undesirable treeingand massing of the fibers and to provide advantageous conditions as willbe herein after described. v 40 The method of pile construction to whichthe present invention applies comprises, broadly, establishing anelectric .field of appreciable strength, for example, having a voltagedrop of 45,000 volts between two relatively fiat, parallel, electrodesthree inches apart; placing a base material, e. g. cloth or paper,coated with an adhesive, within the electric field (preferably paralleland adjacent to one boundary of saidfield) and 50 supplying pile-formingfibers to the region of the electric field. The fibers, initiallycarrying electric charges or becoming electrically charged by induction,move under the influence ofthe electric field and contact with theadhesive in 55 oriented position, i. e. perpendicular to the base,

whereby only one end of each fiber is attached to the base. i

The manner in which these and other objects of the invention arerealized will be described in what follows, reference being had for thepurpose of illustration to the accompanying drawings, in which:

Fig. 1 is a diagrammatic viewof a system comprising apparatus shown insectional elevation and an electric circuit, which embodies certainprinciples of the invention;

Fig. 2 illustrates a system, shown more or less diagrammatically, butfor the most part in sectional elevation, for practicing one embodimentof the invention;

Fig. 3 shows apparatus, in sectional elevation, for practicing theprinciples of the invention in somewhat different manner; and

Fig. 4 is a diagrammatical representation of a circuit which may besubstituted in some cases for the circuit shown in Fig. 1.

Referring to Fig. 1-, numeral 5 designates a more or less air tightcasing in which are supported two electrodes, I and 2, respectively,between which may be set up a strong electric field.. A source ofenergy, to be described later, is connected to electrode I by-electricalconductor 3 and to electrode 2 by conductor 4, the latter electrode, andcasing 5 also, being preferably connected to ground as shown at 6.Electrode l-is insulated from casing 5 by insulating support I and tube8. Tube 8 functions both as an insulating support and as an inletbushing for conductor 3. Electrode 2, which is shown as a screen, issupported from the sides of easing 5 by imperforate plate-like members9', 9. These are free from points or projecting edges, it beingdesirable that no corona discharge emanate from the apparatus while itis energized.

Above electrode 2 is a basket for sitting the 40 fibers to be used inmaking piled surfaces. It

comprises a screen l0; preferably of closer mesh than that of electrode2, a reinforcing band i l,

and a supporting sleeve l2 of fiexible material, i. e. canvas, fromwhich screen It depends. Shaking of screen I0 is accomplishedv by thereciprocal movement of rod l3 brought about inturn by the turning, ofcam H by means not shown. In this embodiment of the invention,

screen l0 and connected parts are connected to ground by conductor l5.

The fibers are carried into the region of the electric field, that is,between electrodes l and 2,

by air flotation; fan i6, connected to the bottom and top of casing 5 byfiues I1 and i8, respec- -tively, being used to move the air throughthe' cilitating the movement of the fibers from the hopper into the airstream passing in flue II.

The manner in which the apparatus is operated in constructing piledsurfaces is set forth in the following description. The material to bepiled, say a sheet of paper, is coated with adhesive and placed uponelectrode with the adhesive facing upwards, as shown at 23. Theelectrodes are now energized, the circuit indicated, to be laterdescribed, being used for that purpose. Fan I6 is started and fibers areadded from the hopper l9 to the air passing in flue l1. Many fibers comefrom storage rather densely packed together and disintegration isnecessary before they can be introduced into the electric field fordeposition on material 23. The agitation provided by the fan and bypassage through the fiues is sometimes sufficient to break up the massesof tangled fibers, but it has been found advantageous to supplement thisaction by further agitation on screen ill. some of the fibers brought toscreen ill by the air stream passing infiue l8 immediately pass throughscreen I and electrode 2 and are deposited by action of the electricfield existing between electrodes and 2 upon the adhesive coveredmaterial 23.

Some of the fibers reach screen ill in clumps, however, and pass throughonly after they have been agitated upon the surface of the'screen andblown with the passing air current.

In this particular embodiment of the invention the force of gravity andthe kinetic energy furnished by the air stream both augment the electric forces in pushing or pulling the fibers down upon the surface ofsheet 23. The air stream must turn at 90 degrees, however, as itapproaches the surface of sheet 23 in order to pass around electrode l,as indicated by the arrows, and enter flue i1 beneath it; but this seemsto be more beneficial than otherwise. The fibers that have been properlyseparated, charged and oriented are pulled down, definitely, to thesurface and adhere to it because of the predominance of the electricforces over any sideward pull set up by the air stream. The fibers whichtree or settle in loose masses over the surface of the pile are blownaway by the air and carried into flue H to be again introduced, afterfurther disintegration, for deposition. As pointed out above, the

screen comprising electrode .2 is of coarser mesh than screen I I); forexample, the former may have 6 openings to the linear inch while thelatter may have 8 or more. This is to assure the ready passage of fibersthrough electrode 2. But sometimes long and rough fibers will build upon screen 2, necessitating the shaking or brushing of this electrode."It is to advantage to keep electrode 2 free from complications andauxiliary members and in careful alignment, parallel to electrode I.This is best accomplished by supporting it as shown, but where shakingand the like must be resorted to, electrode 2 may be eliminated and thebottom surface of screen Hi can be made to function as the top boundaryof the electric field.

- Fig. 2 illustrates apparatus in which the surface to be piled is heldin vertical position. This construction has been found to haveadvantages when the fibers tend to .tree between the electrodes and/orbecome grouped in unattached masses over the uncompleted pile.Unattached fibers can be more positively blown from a vertical surfacethan from horizontal surfaces such as that shown in Fig. 1. Theconstruction illustrated in Fig. 2 also makes possible the piling ofsurfaces while they are moving and permits of humidity control withinthe apparatus.

In Fig. 2, numeral 3| designates the electrode over which material 43,which may be a flexible sheet of fabric, is caused to pass while a. pileis built upon the surface thereof. Electrode 3| is maintained,preferably, at high potential and is supported by insulating means asindicated by member 31. Electrode 3| is opposed by electrode 32, made upof members 32' extending transversely and, in general, parallel to thesurface of electrode 3|. Members 32' are positioned from' onehalf to oneand one-half inches apart, depending upon electrical conditions, thevelocity of the air passing, and other conditions. The lower edges ofmembers 32', the edges closest to electrode 3|; are bent back orotherwise rounded to prevent corona discharge therefrom. With the edgesthus rounded and spaced and. carefully aligned so as to be at an equaldistance from the surface of electrode 3|, members 32' comprise. aboundary for any electric'field established between electrodes 3i and 32that is not essentially different in its characteristics from that to behad with a fiat plate. Electrode members 32' are supported, by means notshown, so their upper edges are in alignment with the bottom, and openend, of wind box 35; and air leaving the wind box is directed, in anoblique direction, by members 32' towards the surface of electrode 3i.Within wind box 36 is a. fiber sifting device made up of flexible sleeve38, screen 39 dependent therefrom, and an agitating device indicated bycrank 40 and connecting rod 4|. H

The electrodes and supports just described are enclosed in a chamber orcasing 35. Casing 35 is preferably'substantially air tight, but as it isdiflicult, although not impossible, to handle material 43-within thecasing, slots are made at 42 and 44 for the entrance and exit of thematerial. Casing 35 is ordinarily made of electric conducting material,grounded by conductor .34, but it is advisable in some cases to make itof non-conducting material, especially that part enclosing highpotential electrode 3| as indicated at a, b, c and d. Side b can bebuilt as a door through which electrode 3| can be inspected andpositioned and the insulation thereabouts can be cleaned. Electricconductor 33 connects electrode 3| to energizing means outside thecasing, such as that indicated in Figs. 1 and 4. It is held in insulatedrelationship with wall d of casing 35 by bushing 45.

- Air, orany suitable gas, is circulated through casing 35 by fan 50,connections to the fan being made by fiues and 52. Fibers are added tothe air stream through hopper 53, the amounts added being controlled bymeasuring wheel 54. The characteristics of the circulating air,especially as regards humidity conditions, are controlled by addingconditioned air and releasing surplus air. Air drier than that of theatmosphere can be obtained by drawing air through drying chamber 55which is connected to fiue 5| by flues 51 and 51', controlbeing securedby valve 58. Dehydra tion of the air is brought about by spreadingcalcium chloride over trays l8 and causing the air to pass over thechloride. The air in the system may be too dry in cold weather.'Humidification can be secured by drawing air into the system throughspray chamber 59, water provided by spray I being evaporated as the air.passes over bailles I. Valve 6! permits close regulation of thehumidified air admitted. Conditioned air admitted for humiditycorrection replaces air already in the system and this is releasedthrough valve 3. The released air carries fibers in common with theother air in circulation and these are collected in bag filter i4,removed through closure 65, and returned to hopper 53. It has been foundadvantageous to so regulate valves 63 and 54 (or 62) and dampers 66 and..61 that the pressure in casing is held at -or very slightly aboveatmospheric pressure. If the pressure is slightly above that of theatmosphere, air passes out slots 42 and 44, whereas at lower pressuresit would enter through them. Of course, by suitable control means, gasesfor special purposes can be introduced into the system. .If the adhesiveon material 43 is accompanied by solvents having vapors which may formexplosive mixtures with air, such mixtures can be avoided by addingcarbon dioxide or other non-supporter oi combustion in appreciablequantity. While ordinarily sparks are not present in the apparatus,improper control may cause the inadvertent presence of sparks andexplosive mixtures of air and vapors are to be avoided.

- The material upon the surface of which ,a pile is to be constructedmay be a fabric ordinarily supplied in roll form as indicated by roll10. It is stretched over guide rolls ll, 12 and I3 and over electrode iiand slowly moved by suitable means such as rolls l5, 15 which haveraised and. corrugated bands at the ends thereof to grasp the sheet 43at the edges and draw it over the other rolls and permit it to bere-rolled as indicated at roll is. The adhesive may be put on v byvarious methods. The method illustrated consists of the use of trough ITwith spreading edge 18 which presses upon or projects towards the fabricas it is stretched over adjustable member I9. The fibers are attached,in positions perpendicular to the surface of the fabric, for the mostpart, as thefabric moves over electrode 3|. The piled material is thenfinished as may be -necessary or desired. Driers and/or vulcanizers,

not shown, may be provided at location 30. A beater 8i and brush 82remove non-attached or poorly attached fibers after the adhesive hasbecome dry. Hoppers 83 and 84 collect loose fibers that may otherwisebecome scattered about the v operating room.

In operating the apparatus shown in Fig. 2 it is important that thefibers be separately floated in the air stream and be conducted into theelectric field in this condition for deposition on the surface to bepiled. The aggregates of fibers introduced through hopper 53 are brokenup to a considerable extent by fan 50 which in- .and tend to "treebetween the. electrodes. these unattached fibers remain over theuncompleted pile, further deposition of oriented fibers suit is easilyascertained. Many of the fibers reach the adhesive covered surface inoriented position; that is, perpendicular to the surface,- and becomefastened at one end to that surface. Some ofthe fibers approach thesurface sidewise for lack of suiflicient electric charge or some otherreason, or become attracted to other fibers If ceases; but bycontrolling the velocity of the air stream, a removal of su'chfibers isrealized and deposition of fibers continues until they are so thicklypacked upon the surface of the material that the material is completelyhidden and a pile factory. Too high a velocity of air in the elec tricfield will move the charged fibers in a dif ferent direction from thedirection the electric field tends to'move, them. But it canbe readilyappreciated that a stream of air moving at a properly chosen velocityand preferably at an angle which causes the air stream to augment theforce of gravity will keep the region of the electric field free ofuncharged and massed fibers and permit the separated and charged fibersto be deposited individually into the pile.

The control of humidity 'has been mentioned above. The fibers commonlyused in making piles, for example, fibers of rayon, silk, and cotton andanimal hairs such as those comprising wool and rabbit fur, are -of smalldiameter and have great surface area as comparedwith their mass. Theyare, therefore; quickly and positively influenced by the moisturecontent of the me-' dium in which they are suspended. The conductivity,.at least the surface conductivity, of the fibers is increased by thesorbed moisture and this alters the rate of distribution of the chargesupon the fibers-and the manner in which they are moved and oriented inthe electric field. It has been found that when the relative humidity ofthe air carrying the fibers is below 40 percent the fibers arenoticeably slower in depositing and forming a pile. A relative humidtyabove percent, on the other hand, tends to cause rapid deposition, butnot .in an orderly manner; treeing and undesirable massing of the fibersresult. With the means illustrated broadly in Fig.

2 and described-above, the air can readily be.

maintained with humidity values between 45 and '75 percent ofsaturation, a humidty range in which depositiomis quite satisfactory.

In the embodiment of the invention shown in moved upwards by action ofthe electric field, and deposited on an adhesive covered surface. Fan 85for moving the air is rotated by motor 81 within ashort tube 86 which issupported by adjustable members 88, 88, within casing 89. Supported uponand above tube 86 is a hood 90 with a top 9! of metal screen or othersuitableopen A mesh material, Within hood 90 'is a scraping I Fig. 3,the fibers are suspended in an air stream,

' projected upwards into an electric \field,j further mechanism 92comprising a plurality of contact' members 93 which, upon rotation ofmechanism 92, by means preferably outside casing 89 and not shown, passin rubbing contact over the inner surface of screen 9|. A transverseplate 94 within tube 88 is for the purpose of preventing rotation of theair stream leaving tube 88.

An electrode 95 is suspended from cover '96 of casing 89 by members 91which are mounted on springs 98. Electrode 95 can be moved downwards ifsufiicient force is exerted upon it to overcome springs 98, but itcannot move upwards because of stops 99. An anvil Iwith a transverselyextending slot I M is mounted on electrode 95. Within slot IOI israpping member I02 which is dependent from rod I which is in turndependent from yoke I08 which rides on cam I0'I. Rod I05 is verticallymovable in bearings I08 and I09 and when yoke I05 drops oil the highpoint of cam I01, spring I03 causes hammer member I04, which ispositively attached to rod I05, to strike strongly upon anvil I00 andsuddenly move and vibrate electrode 95.

An electric field for the depositing of fibers can be establishedbetween screen 9| and electrode 95 if either of these members isproperly insulated. But it has been found more convenient and moreeflicient and in general safer to introduce an intermediate member IIObetween the members mentioned. Member H0 is shown as a screen,preferably 01 one-quarter inch or coarser mesh, although closer mesh canbe used if the screen is effectively shaken. Screen I I0 is bounded by arounded band III and this is supported by a plurality of members H2 andH3 which can reciprocate in bearings H4 and II5 within insulatingsupports H6 and III, respectively. The insulators H6 and III arefastened by clamping members II 8 as closures over holes II9 and'I20,respectively, in the walls of casing 89. Member II3 passes completelythrough insulator III and so functions as an inlet conductor forelectric current supplied through conductor I23 and as a connection tothe agitating mechanism designated by numeral I2I. A, connecting linkI22 of insulating material is inserted between member H3 and agitatingmechanism I2I so the latter may be maintained at ground potential.

The apparatus shown in Fig. 3 is commonly used to build piles upon thesurfaces 01' paper and textile fabrics. Roll I25 indicates a supply ofcloth that is guided by rolls I26 and I2! to and from the under surfaceof electrode 95. Rolls I28, I28, in adjustable carriage I29, positiontravelling cloth sheet I25 as it is coated with adhesive from aspreading device I30 similar to those used in coating so-called oilcloth. The fibers or other pile forming elements are introduced into theapparatus through supply bln I3I, a plunger with handle I32 being usedto force the fibers'downwards when necessary. Air, I .or gases forconditioning the air or other gaseous medium within the apparatus, canbe brought in through pipe I33 from any suitable supply' as indicated bychamber I34.

In operating the apparatus shown in Fig. 3, the high potential side of asource of unidirectional current is connected to conductor I23, theother side being connected to conductor I24 and to ground. The devices,not shown, for drawing sheet I25 through the apparatus, are set inmotion and adhesive is applied to said sheet by spreader I30. Motor 81is' started and fibers are fed into the air current setup by fan 85.Scraper 92 is made to revolve. The volume and velocity of air passingthrough screen 9I is regulated by altering the speed of motor 81 and byaltering the air inlet to the fan by raising or lowering sleeve 86 withadjustable supports 88, 88. It should be pointed out that when thefibers are easily disentangled and separated by the fan, 7

screen 9| and scraper 92 are not needed and can be removed, a funnel afew inches high on top of sleeve 86 being then used to direct the fiberstowards the electrodes above.

Adjustments in the position of screen electrode H0 can be made throughclamps II8, but in general the position of electrode I I0 is definitelyfixed at from two and one-half to three and one-half inches below, andparallel to, electrode 95. Changes in the strength of the electric fieldcan be made by controlling the electric circuit conditions. The voltagedifference impressed between the electrodes, as described, is from25,000 to 50,000 volts and the screen electrode H0 is commonly madenegative except where it is advisable to alternate the polarity of thefield.

As the fibers begin to deposit on sheet I25, the means, not shown, forrotating cam I0! is set in motion to turn cam I01 at from 20 to 80 R. P.M. This causes sheet I25 to be rapped rigorously by member I02 where itpasses under slot IM and imparts a more gentle vibration to all of thatportion of sheet I25 which is held against the under side of electrode95. Any fibers not attached to sheet I25 by the adhesive are thus jarredaway from the pile to be recirculated. In the use of this constructionand with this method of operationit is an easy matter to cause theunattached fibers to leave the pile because the force of gravity pullsdirectly away from the pile surface and the horizontal components of theair stream forces sweep the fibers along. to the sides of the apparatus,down which they are carried to the fan inlet.

It is an important object in the present invention to energize theelectrodes comprised in the apparatus described above in effectivemanner. An electric circuit for such purpose is diagrammaticallyillustrated in Fig. 1. A low voltage alternating current source I40, sayat 220 volts and 60 cycles, is connected through a voltage controlresistance HI and a double throw reversing switch I42 to a step uptransformer I44. The

high potential terminals of the transformer are connected to stationaryshoes I45 and I45, respectively, offmechanical rectifying switch I". Theswitch is turned by synchronous motor I in synchronism with the supplycurrent, with the result that stationary shoes I48 and I49 of therectifier are always connected to the high potential current supply atconstant polarity, that is, one shoe is always positive and the other isalways negative. Shoe I48 is shown connected through conductor I54 anddampening or loading resistance I52 and shunting switch I53 to ground 6and the grounded parts of the pile forming apparatus through conductors4 and I5. Shoe I49 is shown connected to insulated electrode I throughconductors I55 and 3. Fibers can be most effectively charged, oriented,and deposited with an electric field of constant polarity and a director rectified current source is preferably utilized, therefore, inenergizing the electrodes. But it has been discovered that, in the useof a constantly applied electric field, certain undesirable conditionsbecome emphasized. Treeing of fibers, once begun, tends to continue andmakes it necessary to operate the scouring air streams andrappingdevices with great diligence. Also with a constantly applied potential asheet of insulating material being piled becomes very strongly attractedto the electrode over which it is passing. It has been found that thesetendencies can be checked if the polarity of the electric field is'occasionally reversed. This is done in the circuit of Fig. 1, forexample, by operating reversing switch I42 with an automatic device,

used instead of a mechanical rectifier.

not shown, that causes the grounded side of the circuit, connected toshoe I48, to be .alternately negative, for example, for two to fiveseconds and then positive for one-half to two seconds. The high voltageelectrode I is at opposite polarity to that of electrode 2 during thesame periods, of course.

Very rapid reversals, in synchronism with the alternating currentsource, have been found advantageous at times. This condition isobtained by shifting rectifier I41 with relation to the revolvingfieldof synchronous motor I50 by clamping adjustable coupling II in adifferent circumferential position. In this manner electrode I can bemaintained, say, positive and at high potential, for most of the halfcycle and negative and at lower voltage for a short part of the cycle.In other words, through what might be called a poor setting ofthe'rectifier, rectification is not complete and a short energization atopposite polarity follows or precedes each half wave of given polarity.Stoss or steep wave front impulses have also been used with good effectin some depositions. This condition is obtained by opening switch I53and inserting a condenser I51 and a spark gap I56 into the circuit asshown. The Stoss circuit will be more effective if a load I58 requiringconsiderable current is placed across leads I54 and I55.

Vacuum tube or hot cathode reotifiers can be Fig. 4 shows the use of asingle hot cathode rectifier I59 which will permit half waveenergization at constant polarity. To effect reversal of polarity withthis type of rectifier in the circuit,'the reversing means must beplaced on the high potential side of the transformer as illustrated bythe use of switch I60. Switch I60, made up of conducting members IBIsupported by insulating member I62, will, upon rotation or uponoscilla-.

tion through 90 mechanical degrees, alternately connect terminal I63 ofrectifier I59, which is always negative, With high potential lead I55and with ground. In oscillating switch I60, a longer pause is made atone set of connections than at the other, thus permitting energizationat one polarity for longer periods than at the other face by afilxingattenuated materials thereto comprising opposed electrode meansinsulated from each other, one of said electrodes being foraminous,means for establishing an electric field between said electrodes, meansfor establishing a gas stream through said foraminous electrode and intothe electric field between said electrodes, and means for introducingpile forming material into said gas stream.

2. Apparatus for forming a pile upon a surface by afiixing attentuatedmaterials thereto comprising superposed electrode means insulated fromeach other, one of said electrodes being foraminous, means forestablishing an electric field between said electrodes, means forestablishing a gas stream through said foraminous electrode and into theelectric field between said electrodes, and means for introducing pileforming material into said gas stream.

3. Apparatus for forming a pile upon a surface by afiixing attenuatedmaterials thereto comprising superposed electrode means insulated fromeach other, the upper of said electrodes being foraminous, means forestablishing an electric field between said electrodes, means forestablishing a gas stream through said foraminous electrode andIinto theelectric field between said electrodes, and means for introducing pileforming material into said gas stream.

4. Apparatus for forming a pile upon a surface by aflixmg attenuatedmaterials thereto comprising superposed electrode means insulated fromeach other, the lower of said electrodes being foraminous, means forestablishing an electric field between said electrodes, means forestablishing a gas stream through said foraminous electrode and into theelectric field between said electrodes, and means for introducing pileform-.

ing material into said gas stream.

5.. Apparatus for forming a pile upon a surface by afiixing attenuatedmaterials thereto comprising opposed electrodes insulated from oneanother, means for establishing an electric field between saidelectrodes, means for passing a web of foundation material through saidfield adja-- cent one of said electrodes, means constituting a conduitfor directing a gas stream between said electrodes, means for impartingmotion to the gas stream in said conduit, means for introducing pileforming material into said gas stream and means. in said conduit forbreaking up clumps of the pile forming material.

6. Apparatus for forming a pile upon a surface by aflixing attenuatedmaterials thereto comprising superposed electrode means insulated fromeach other, the lower of said electrodes being foraminous, means forestablishing an electric field between said electrodes, means foragitating the foraminous electrode, means for establishing a gas streamthrough said foraminous electrode and into the electric field betweensaid electrodes, and means for introducing pile forming material intosaid gas stream.

'7. Apparatus for forming a. pile upon a surface by afiixing attenuatedmaterials thereto comprising opposed electrode means insulated from eachother, one of said electrodes being foraminous, means for establishingan electric field between said electrodes, means for passing a web offoundation material through said electric field adjacent the electrodeopposing the foraminous electrode, means for establishing a gas streamthrough said foraminous electrode and into the electric field betweensaid electrodes, and means for introducing pile forming material intosaid gas stream.

8. A method of forming pile-surfaced materials, which comprisesestablishing an electric rials, which comprises establishing an electricfield between opposed electrode structures, positioning anadhesive-surfaced foundation material between said electrodes,suspending masses of pile forming materials in a gas stream,disintegrating said masses of pile forming materials by passing said gasstream through a foraminous member, and directing the gas streamcontain- I ing the suspended material into the region of the electricfield.

10. A method of forming'pile-surfaced materials, which comprisesestablishing an electric field between opposed electrode structures,posi-' between said electrodes, suspending pile formingmaterials in agas stream, directing the gas stream containing the suspended materialinto the region of the electric field, and periodically alternating thepolarity of the electric field with periods of constant polarity of atleast about onehalf second.

12. A method of forming pile-surfaced materials, which comprisesestablishing an electric field between opposed electrode structures,positioning an adhesive-surfaced foundation material between saidelectrodes, suspending pile forming materials in a gas stream, directingthe gas stream containing the suspended material into the region of theelectric field, and periodically alternating the polarity of theelectric field with a period substantially greater than that ofcommercial alternating current.

13. A method of forming pile-surfaced materials, which comprisesestablishing an electric field between opposed electrode structures,positioning an adhesive-surfaced foundation material between saidelectrodes, suspending pile forming materials in a gas stream, anddirecting the gas stream containing the suspendedmaterial through one ofsaid electrode structures into the region of the electric field whileagitating the electrode through which the gas stream passes.

14. A method of forming pile-surfaced materials, which comprisesestablishing an electric field between opposed electrode structures,positioning an adhesive-surfaced foundation material between saidelectrodes, suspending pile forming materials in a gas stream, directingthe gas stream containing the suspended material through one of saidelectrode structures into the region of the electric field whileagitating the electrode through which the gas stream passes, andperiodically alternating the polarity of the electric field with periodsof constant polarity of at least about one-half second.

15. In the production of piled surfaces by passing a stream of gascontaining pile forming material adjacent an adhesive-surfacedfoundation material positioned in an electric field, the

step comprising adding a conditioning medium to the stream of gaswhereby the conductivity of the pile forming material is altered.

16. In the production of piled surfaces by passing a stream of gascontaining pile forming material adjacent an adhesive-surfacedfoundation material positioned in an electric field, the step comprisingregulating the humidity of the gas stream to a predetermined degree.-

17. In the production of piled surfaces by passing a stream of gascontaining pile forming material adjacent an adhesive-surfacedfoundation material positioned in an electric field, the step comprisingadding gaseous medium of predetermined humidityto said gas stream.

18. In the production of pile surfaces by passing a stream of gascontaining pile forming material adjacent an adhesive-surfacedfoundation material positioned in an electric field, the step comprisingmaintaining the humidity of the gas stream at a predetermined degreebetween about 40 percent and about percent relative humidity.

19. A method of forming piled surfaced materials, comprisingestablishing an electric field between opposed electrode structures,bringing pile forming fibers into said electric field adjacent anadhesive-surfaced foundation material, and controlling the electricaldeposition of the fibers by controlling the surface conductively of thefibers.

20. In the production of piled surfaces by passing a stream of gascontaining electrically charged pile forming material adjacent anadhesive-surfaced foundation material positioned in an electric field,the step comprising regulating the humidity of the gas stream to apredetermined degree.

21. Apparatus for forming a pile upon a surface by aflixing attenuatedmaterials thereto comprising opposed electrode means insulated fom eachother, one of said electrodes being foraminous, means for establishingan electric field between said electrodes, means for establishing a gasstream through said foraminous electrode and into the electric fieldbetween said electrodes, means for introducing pile forming materialinto said gas stream, said foraminous electrode having openings adaptedto break clumps of said pile forming material into individual fibers.

22. Apparatus for forming a pile upon a surface by aflixing attenuatedmaterials thereto comprising opposed electrode means insulated from eachother, one of said electrodes being foraminous, means for establishingan electric field between said electrodes, means for establishing a gasstream through said foraminous electrode and into the electric fieldbetween said electrodes, means for introducing pile forming materialinto said gas stream, and means cooperating with said foraminouselectrode for breaking clumps of said pile forming material intoindividual fibers.

23. Apparatus for forming a pile upon a surface by aflixing attenuatedmaterials thereto comprising opposed electrodes insulated from oneanother, means for establishing an electric field between saidelectrodes, means constituting a conduit for directing a gas streambetween said electrodes, means for imparting motion to the gas stream insaid conduit, means for introducing pile forming material into said gasstream and beating means in said conduit for breaking up clumps of thepile forming material.

24. A method of forming pile-surfaced materials which comprisesestablishing an electric field between opposed electrode structures,positioning an adhesive-surfaced foundation material between saidelectrodes, bringing pile-forming fibers into the electric field andperiodically alternating the polarity of the electric field with periodsof constant polarity of at least about onehalf second.

25. A method of forming pile-surfaced materials, comprising establishingan electric field between opposed electrode structures, bringingpileforming fibers into said electric field adjacent anadhesive-surfaced foundation material, and

controlling the electrical deposition of the fibers by controlling theconductivity of the fibers.

26. -A method of forming pile-surfaced materials, comprisingestablishing an electric field between opposed electrode structures,bringing pileforming fibers into said electric field adjacent anadhesive-surfaced foundation material, and controlling the electricaldeposition of the fibers by controlling the moisture content of thefibers.

27. A method of forming pile-surfaced materials which comprisesestablishing an electric field between opposed electrode structures,positioning an adhesive-surfaced foundation material between saidelectrodes, bringing pile-forming fibers into the electric field andperiodically alternating the polarity of the electric field withpotentials of substantially different voltage in periods of alternatepolarity.

.28. A method of forming pile-surfaced material which comprisesestablishing an electric field of periodically alternating polarity,positioning an adhesive-surfaced foundation material in said field andbringing comminuted fibrous material into, the field in condition to bedeposited thereon, thereby to produce a uniform pile surface having thefibers oriented in endwise position on the adhesive surfaced material.

29. In the production of pile-surfaced material, the method whichcomprises feeding alon a predetermined path an adhesive-coatedfoundation-materia1 creating an electrostatic field of alternatingpolarity intersecting said path and sive-surfaced foundation materialand means for introducingpile-forming fibers into said field.

31. Apparatus for forming pile-surfaced material comprising means forfeeding along a predetermined path a foundation material, means forcoating the foundation material with adhesive, means for creating anelectric field of alternating potential intersecting said path and meansfor introducing pile-forming fibers into said field.

HARRY A. WIN'I'ERMUTE.

